Build a sauna on deck - where ancillary buildings' heights are measured from if sited on a deck?

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Posted by: from Toronto
3/21/2022 at 10:02:51 AM

Built a nice deck last year and would like to put a sauna on it this year. Maximum height (assume without variance allowance from committee of adjustments) for ancillary buildings here in Toronto is 2.5M (8'2") but I can't find in the building code defining from where the maximum 2.5M (8'2") height starts. (i.e deck surface or established grade, or grade under deck)

Deck surface averages 21" above ground where sauna would be sited. Even though our lot's "established grade" might be 3"-4" higher than grade under proposed sauna, if not using deck as the starting point, but rather the established grade or grade under deck, the ceiling of the would have to be too low if complying with the 2.5 meter height restriction.

Can anyone point out in the code where ancillary buildings' heights are measured from if sited on a deck?

Just want to build a sauna and not deal with permits, allowances etc.

Thanks for you help!

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Richard in Edmonton
Date/Time3/22/2022 at 11:21:23 PM

Grade is defined in the Building Code. Generally speaking it is the average height of the ground adjacent to the building. There are special provisions for steeply sloping sites where a building may be 'stepped', and also special provisions to allow for things like such as patios or entry doors on an apartment building where the grade is allowed to be lowered without penalizing the grade definition.

in your case grade should simply be the surrounding yard area adjacent to the deck. If the deck is attached to the home this may be considered a home addition as opposed to an accessory building; however likely this wont impact any development rules. Development regulations can have their own definition or interpretation of grade and not necessarily agree with the Building Code.

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Date/Time3/24/2022 at 1:55:16 PM

Not sure of Ontario code. I now it could be done here.. But!! I have done builds on decks (hot-tub & enclosure, roofed gazebos etc.) and you can't do it without "reinforcing" the deck underneath. Depending on weight of sauna you may have to also add more pilings, so expect to disassemble deck partly to upgrade. Also never ignore permits or legal code! when you go to sell a house, this will come back to bite you in the butt or be a safety hazard. Do it legal and right once, or cheap and wrong and pay for it sooner or later.

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